Any recommended keyboard accessibility solution for user to navigation to the menu efficiently? [closed]

We have this top bar on the page and the menu is on the left. Every page has lots of content within it (could have 100+ tabbable elements).

For screen users, they have shortcuts to invoke the navigation.

But for motor disability users or people who want to use keyboard only, it's very inefficient to navigate between pages, as when they are done with a page they might be at the bottom of the page and have to use shift + tab to go all the way to the top to go to another page.

Anyone has seen any webpage has a quick way to open the navigation menu by keyboard no matter where you are on the page? I know pressing 'Home + End' to the top or bottom of the page, however, the focus remains at where you were previously, so when you tab again it jumps back to the next item you were on. I'm reluctant to introduce custom keys as that might conflict with screen reader/browser or system shortcuts.

This is not a programming question, not related to coding. I'm looking for a good practice suggestion.